Automatic ventilator



Nov. .26, 1929. MCQUISTAN 1,737,954?

AUTOMATI G VENTILATOR Filed May 9, 1928 glwuentoz J :PM Q Q abfomwq Patented Nov. 26, 1929 DUNCAN A. HCQ'UISTAN, OF WALTHILL'NEBBASKA.

AUTOHATIC VENTILATOR Application filed Kay 9, 1928. Serial No. 276,439.

My invention relates to ventilators and has for its object to provide, in combination w th a ventilator, a valve gate, together with mechanism for automatically closing andopening said gate, said mechanism being heatcontrolled in such a way as to decrease the ventilating opening as the temperature of the air within the ventilator drops and to increase the ventilating opening as the tempero ature rises.

A ventilator of this type is particularly useful in connection with brooders,.hog houses, and the like and is ca able of exerting considerable stabilizing e ect upon temperatures within a heated building, tending to decrease variations in temperature.

More particularly, it is my object to provide such a heat-controlled ventilator employing a simple, durable and inexpensive construction including a thermostat, a movable valve gateand connecting lever mechanism forma-gnifying the movement of the thermostat and transmitting it to the valve gate in such a manner as to obtain a range of movement suflicient to swing the gate from completely open to completely closed position.

A further object is to provide such an arrangement wherein a plurality of thermo- 80 static units may be successfully employed, operating in synchronism with each other without unduly complicating the construction.

. The use of several thermostatic units multiplies the power which is obtained therefrom.

Another object is to provide means for adjusting the position of the gate relative to the thermostat units, adjustment being accomplished b turning a single turn-buckle or nipple. his is accomplished by mounting the thermostatic units and the multi lying lever arran ement together on a single racket, the brac et being adjustable so as to vary the position of the multiplying lever relative to the valve gate without disturbing the relation of the multiplying lever and the thermostatic units.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the ob'ects contemplated are attained, as hereina ter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical, sectional viewof the ventilator taken transversely through the axis of the valve gate. i

Fig. 2 is a vertical, sectional view through the ventilator,,taken on the line 2-2 of Fig. 1. 60

Fig. 3 is an inverted plan view of the ventilator. I

The ventilator of'my invention comprises a flue 10, having a hood 11 at its upper extrenfaity and flanges 12 for attachment to a roo The valve gate13 is secured to a shaft 14, WhlCh is j ournalled in the walls of the flue 10, exactly bisecting the cross-sectional area of the'flue.

The gate 13 is longer in a direction transverse to the shaft 14 than the distance between the walls 10 in a direction transverse to the shaft 14. Thus the gate will contact with these walls when it isin an inclined position, as shown in dotted lines at 15 in Fig. 1.

The gate 13 is shaped so as to correspond to the cross-sectional shape of the flue 10 in the plane of the position 15. It will be understood that although the flue 10 is shown as 30 being rectangular that it might be of some other shape in cross section without chang ing the invention.

Secured to the wall of the flue 10 near the lower extremity thereof, substantially equidistant from the ends of the shaft 14 is a bracket member 16. The bracket member 16 is formed with an upwardly projecting, threaded stud 17 which is spaced from a wall of the flue. A turn buckle or nipple 18 is 99 threaded on the upper endof the stud 17 and a bracket member 19 is supported by the nipple 18.being provided with a threaded end 20, threaded oppositely to the threaded or-. tion 17 and received in the upper end 02 the nipple 18.

Secured to the bracket 19 is a cross bar 21, which extends laterally parallel to the shaft 14 and which carries at its ends a pair of thermostatic wafers 22. The wafers 22 are v thereof.

' the yoke 23 midway between the thermostatic wafers 22, so that expansion of the wafers will cause the yoke 23 to move the arm 26 outwardly.

The end of the arm 25 is connected by means ofa link 01' links 28 to a short lever 29, secured to the gate 13 near the shaft 14 A spring 30 connects the arm 25 with a portion of the bracket member 16, such as the loop 30. The spring might be secured to the wall of the flue 10 but the bracket 16 forms a convenient anchor for the spring. The spring 30 is arranged under tension so as to urge the arm 25 downwardly and to swing the gate 13 toward the dotted line position 15.

The pull of the spring 30 is resisted and counteracted by the expansion of the thermostatic wafers 22.

As has already been mentioned, the use of several wafers increases the amount of power which may be derived from the changes in temperature. The bridging yoke 23 serves to equalize the movement of the two wafers and to transmit a single push to the bell crank lever.

Adjustment of the turn buckle 18 moves the bracket member 19 bodily upwards, carrying the bar 21 and the thermostatic wafers 22 along with it and simultaneously raising the fulcrum of the bell crank lever. In this way, the relation of the bell crank lever to the thermostatic wafers is undisturbed while the relation of the bell crank lever to the gate is changed. The raising of the fulcrum correspondingly raises the outer end of the arm 25 for any fixed position of the arm relative to the thermostatic Wafers and therefore transmits movement to the gate, adjusting it from the dotted line position 15 toward its vertical position shown in full lines.

The action of the bell crank lever in transmitting movement to the gate is thought to be obvious. In the contracted position of the thermostatic waiers, the bell crank lever will assume the position shown in dotted lines in Fig. 1 moving the lever 29 downwardly to throw the gate to the position 15.

Intermediate positions of the thermostatic wafers will result in intermediate positions of the gate 13. The spring 30 will maintain the arm 26 at all times in engagement with oke 23. i T e distance from the end of the lever 29 to the shaft 14 is approximately one-sixth of the distance from an end of the gate 13 to the shaft 14: and the arm 26 is approximately onehalf the length of the arm 25, thereby gaining a multiplied movement at the end of the arm 25 of two to one, as compared with the movement of the thermostatic wafers and increasing the arc of swing of the ends of the gate 13 over the movement of the lever 29 substantially six times.

The advantage of the regulation of the gate has already been mentioned, the heated air being retained in a house equipped with the ventilator when the ventilator is closed vand being allowed to escape when it is opened.

Some changes may be made in the construct-ion and arrangement of the parts of my invention without departing from the real spirit and'purpose of my invention, and it is m intention to cover by my claims, any modlfied forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a ventilator of the type adapted to be installed on the roof of a housing structure or the like, a flue of limited height, a gate mounted in said flue for swinging movement, a bracket having an adjustable portion, a thermostatic device mounted on said portion to expand and contract transversely of the flue, a bell crank lever fulcrumed on said portion, having a short. portion engaging said thermostatic device and a long portion extended to a position near the axis of the gate, and a link connecting the long portion with the gate, said link having a pivotal connection with both the lever and the gate.

2. In a ventilator of the type adapted to be installed on the roof of a housing structure or the like, a flue of limited height, a ga e swingingly mounted in said flue, a bracket secured to the flue and having an adjustable portion, a thermostatic device carried by said adjustable portion to expand and'contract transversely of the flue, and lever means including a bell crank lever fulcrumed on said adjustable portion, connecting the thermostatic device with the ate.

3. In a ventilator o the type adapted to be installed on the roof of ahousing structure or the like, a flue of limited height, a gate ture or the like, a flue of limited height, a gate mounted in said flue for swin ing movement, a bracket, a thermostatic device mounted onsaid bracket to expand and contract transversely of the flue, a bell crank lever fulcrumed on said bracket, having a short portion engaging said thermostatic device and a long portion extended to a position near the axis of the gate, and a link connecting the long portion with the gate, said link having a pivotal connection with both the lever and the gate, and a spring secured under tension be tween the gate and the flue, adapted to oppose the action of the thermostatic device.

5. In a ventilator of the type adapted to be installed on the roof of a housing structure or the like, a flue of limited height, a gate swingingly mounted in said fine, a bracket secured to the flue and having an adjustable portion, a transverse bar carried by said adjustable portion, a pair of thermostatic devices supported on said bar, on either side of the bracket to expand and contract transversely of the flue, a-yoke connecting the movable portions of the thermostatic devices, and a lever means including a bell crank lever'fulcrumed upon said adj ustable portion, connecting the yoke with the gate.

6. In a ventilator of the t e adapted to be installed on the roof of a ousing structure or the like, a flue of limited height, a

ate swingingly mounted on an axis bisectmg it and disposed transversely to the longitudinal axis of the flue, a short lever secured to the gate and extending laterally from the plane thereof, a thermostatic device supported on a wall of the flue to expand and contract transversely of the flue, a bell-crank lever fulcrumed above the thermostatic device, having a short arm engaging the same,

a long arm extending to a portion near the axis of the gate, and a link connecting said long arm with the short lover of the gate.

7. In a ventilator of the type adapted to 4 be installed on the roof of a housing structure or the like, a flue of limited height, a gate swingingly mounted on an axis bisecting it and disposed transversely to the longitudinal axis of the flue, a short lever secured to the gate and extending laterally from the plane thereof, a thermostatic device supported on a wall of the flue to expand and contract transversely of the flue, a bell-crank lever fulcrumed above'the thermostatic device, having a short arm engaging the same,

a long arm extending to a portion near the Y axis of the gate, a link connecting said long arm with the short lever of the gate, and a spring connected under tension to the gate and to the wall of the ventilator below the bell-crank lever.

Signed this 7th day of May, 1928, in the county of Woodbury and State of Iowa.

DUNCAN A. MoQUISTAN. 

